BS EN 61439-1:2011 BSI Standards Publication Low-voltage switchgear and controlgear assemblies Part 1: General rules BRITISH STANDARD BS EN 61439-1:2011 National foreword This British Standard is the UK implementation of EN 61439-1:2011 It is identical to IEC 61439-1:2011 It supersedes BS EN 61439-1:2009, which will be withdrawn on 23 September 2014 The UK participation in its preparation was entrusted by Technical Committee PEL/17, Switchgear, controlgear, and HV-LV co-ordination, to Subcommittee PEL/17/3, Low voltage switchgear and controlgear assemblies A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © BSI 2011 ISBN 978 580 67925 ICS 29.130.20 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2011 Amendments issued since publication Amd No Date Text affected BS EN 61439-1:2011 EUROPEAN STANDARD EN 61439-1 NORME EUROPÉENNE EUROPÄISCHE NORM October 2011 ICS 29.130.20 Supersedes EN 61439-1:2009 English version Low-voltage switchgear and controlgear assemblies Part 1: General rules (IEC 61439-1:2011) Ensembles d'appareillage basse tension Partie 1: Règles générales (CEI 61439-1:2011) NiederspannungsSchaltgerätekombinationen Teil 1: Allgemeine Festlegungen (IEC 61439-1:2011) This European Standard was approved by CENELEC on 2011-09-23 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels © 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 61439-1:2011 E BS EN 61439-1:2011 EN 61439-1:2011 -2- Foreword The text of document 17D/441/FDIS, future edition of IEC 61439-1, prepared by SC 17D, "Low-voltage switchgear and controlgear assemblies", of IEC TC 17, "Switchgear and controlgear" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61439-1:2011 The following dates are fixed: • • latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with the document have to be withdrawn (dop) 2012-06-23 (dow) 2014-09-23 This document supersedes EN 61439-1:2009 EN 61439-1:2011 includes the following significant technical changes with respect to EN 61439-1:2009: — revision of service conditions in Clause 7; — numerous changes regarding verification methods in Clause 10; — modification of routine verification in respect of clearances and creepage distances (see 11.3); — adaption of the tables in Annex C and Annex D to the revised requirements and verification methods; — shifting of tables from Annex H to new Annex N; — new Annex O with guidance on temperature rise verification; — new Annex P with a verification method for short-circuit withstand strength (integration of the content of IEC/TR 61117); — update of normative references; — general editorial review NOTE It should be noted that when a dated reference to EN 60439-1 is made in another Part of the EN 60439 series of assembly standards not yet transferred into the new EN 61439 series, the superseded EN 60439-1 still applies (see also the Introduction below) Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights This document has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s) For the relationship with EU Directive see informative Annex ZZ, which is an integral part of this document -3- BS EN 61439-1:2011 EN 61439-1:2011 Endorsement notice The text of the International Standard IEC 61439-1:2011 was approved by CENELEC as a European Standard without any modification In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60038 NOTE Harmonized as EN 60038 IEC 60079 series NOTE Harmonized in EN 60079 series IEC 60112:2003 NOTE Harmonized as EN 60112:2003 (not modified) IEC 60204 series NOTE Harmonized in EN 60204 series IEC 60204-1 NOTE Harmonized as EN 60204-1 IEC 60228:2004 NOTE Harmonized as EN 60228:2005 (not modified) IEC 60947 series NOTE Harmonized in EN 60947 series IEC 61000-3-2:2005 NOTE Harmonized as EN 61000-3-2:2006 (not modified) IEC 61000-3-3 NOTE Harmonized as EN 61000-3-3 IEC 61000-3-11 NOTE Harmonized as EN 61000-3-11 IEC 61000-3-12 NOTE Harmonized as EN 61000-3-12 IEC 61000-6-1 NOTE Harmonized as EN 61000-6-1 IEC 61000-6-2 NOTE Harmonized as EN 61000-6-2 IEC 61000-6-3 NOTE Harmonized as EN 61000-6-3 IEC 61082 series NOTE Harmonized in EN 61082 series IEC 61140:2001 NOTE Harmonized as EN 61140:2002 (not modified) IEC 61241 series NOTE Harmonized in EN 61241 series BS EN 61439-1:2011 EN 61439-1:2011 -4- Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies Publication Year Title EN/HD Year IEC 60068-2-2 2007 Environmental testing Part 2-2: Tests - Test B: Dry heat EN 60068-2-2 2007 IEC 60068-2-11 1981 Environmental testing Part 2: Tests - Test Ka: Salt mist EN 60068-2-11 1999 IEC 60068-2-30 2005 Environmental testing EN 60068-2-30 Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle) 2005 IEC 60073 2002 Basic and safety principles for man-machine EN 60073 interface, marking and identification - Coding principles for indicators and actuators 2002 IEC 60085 2007 Electrical insulation - Thermal evaluation and EN 60085 designation 2008 IEC 60216 Series Electrical insulating materials - Properties of thermal endurance EN 60216 1) HD 21.3 S3 + A1 + A2 IEC 60227-3 (mod) 1993 Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V Part 3: Non-sheathed cables for fixed wiring IEC 60245-3 Rubber insulated cables - Rated voltages up to and including 450/750 V Part 3: Heat resistant silicone insulated cables 1994 IEC 60245-4 (mod) 1994 Series 1995 1999 2008 - 2) Cables of rated voltages up to and including HD 22.4 S3 450/750 V and having cross-linked insulation - + A1 Part 4: Cords and flexible cables + A2 1995 1999 2002 IEC 60364 Series Low-voltage electrical installations HD 60364 Series IEC 60364-4-41 (mod) 2005 Low-voltage electrical installations Part 4-41: Protection for safety - Protection against electric shock HD 60364-4-41 + corr July 2007 2007 IEC 60364-4-44 (mod) 2007 Low voltage electrical installations Part 4-44: Protection for safety - Protection against voltage disturbances and electromagnetic disturbances HD 60364-4-444 + corr July 2010 2010 IEC 60364-5-52 (mod) 2009 HD 60364-5-52 Low-voltage electrical installations Part 5-52: Selection and erection of electrical equipment - Wiring systems 2011 IEC 60364-5-53 2001 Electrical installations of buildings Part 5-53: Selection and erection of electrical equipment - Isolation, switching and control - 1) HD 21.3 S3 is superseded by EN 50525-2-31:2011 2) HD 22.4 S3 is superseded by HD 22.4 S4:2004 BS EN 61439-1:2011 EN 61439-1:2011 -5Publication Year Title IEC 60364-5-54 2011 Low-voltage electrical installations HD 60364-5-54 Part 5-54: Selection and erection of electrical equipment - Earthing arrangements and protective conductors IEC 60439 Series Low-voltage switchgear and controlgear assemblies IEC 60445 2010 Basic and safety principles for man-machine EN 60445 interface, marking and identification Identification of equipment terminals, conductor terminations and conductors 2010 IEC 60447 2004 Basic and safety principles for man-machine EN 60447 interface, marking and identification Actuating principles 2004 IEC 60529 1989 Degrees of protection provided by enclosures EN 60529 (IP Code) + corr May 1991 1993 IEC 60664-1 2007 Insulation coordination for equipment within low-voltage systems Part 1: Principles, requirements and tests 2007 IEC 60695-2-10 2000 Fire hazard testing EN 60695-2-10 Part 2-10: Glowing/hot-wire based test methods - Glow-wire apparatus and common test procedure 2001 IEC 60695-2-11 2000 EN 60695-2-11 Fire hazard testing Part 2-11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products 2001 IEC 60695-11-5 2004 Fire hazard testing Part 11-5: Test flames - Needle-flame test method - Apparatus, confirmatory test arrangement and guidance 2005 IEC 60865-1 1993 Short-circuit currents - Calculation of effects - EN 60865-1 Part 1: Definitions and calculation methods IEC/TR3 60890 1987 A method of temperature-rise assessment by CLC/TR 60890 extrapolation for partially type-tested assemblies (PTTA) of low-voltage switchgear and controlgear 2002 IEC 60947-1 2007 Low-voltage switchgear and controlgear Part 1: General rules 2007 IEC 61000-4-2 2008 EN 61000-4-2 Electromagnetic compatibility (EMC) Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test 2009 IEC 61000-4-3 2006 Electromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test EN 61000-4-3 2006 IEC 61000-4-4 2004 Electromagnetic compatibility (EMC) Part 4-4: Testing and measurement techniques - Electrical fast transient/burst immunity test EN 61000-4-4 2004 3) EN/HD Year EN 60439 Series EN 60664-1 EN 60695-11-5 1993 3) CLC/TR 60890 includes A1:1995 to IEC/TR3 60890 + corr March 1988 EN 60947-1 2011 BS EN 61439-1:2011 EN 61439-1:2011 -6- Publication Year Title EN/HD Year IEC 61000-4-5 2005 Electromagnetic compatibility (EMC) Part 4-5: Testing and measurement techniques - Surge immunity test EN 61000-4-5 2006 IEC 61000-4-6 2008 Electromagnetic compatibility (EMC) Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields EN 61000-4-6 2009 IEC 61000-4-8 2009 EN 61000-4-8 Electromagnetic compatibility (EMC) Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test 2010 IEC 61000-4-11 2004 Electromagnetic compatibility (EMC) EN 61000-4-11 Part 4-11: Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests 2004 IEC 61000-4-13 2002 EN 61000-4-13 Electromagnetic compatibility (EMC) Part 4-13: Testing and measurement techniques - Harmonics and interharmonics including mains signalling at a.c power port, low frequency immunity tests 2002 IEC 61000-6-4 2006 Electromagnetic compatibility (EMC) Part 6-4: Generic standards - Emission standard for industrial environments EN 61000-6-4 2007 IEC 61082-1 - Preparation of documents used in electrotechnology Part 1: Rules EN 61082-1 - IEC 61180 Series High-voltage test techniques for low-voltage equipment EN 61180 Series IEC/TS 61201 2007 - - IEC 61439 Series Low-voltage switchgear and controlgear assemblies EN 61439 Series IEC 62208 - Empty enclosures for low-voltage switchgear EN 62208 and controlgear assemblies - General requirements - IEC 62262 2002 Degrees of protection provided by enclosures EN 62262 for electrical equipment against external mechanical impacts (IK code) 2002 IEC 81346-1 - Industrial systems, installations and equipment and industrial products Structuring principles and reference designations Part 1: Basic rules EN 81346-1 - IEC 81346-2 - EN 81346-2 Industrial systems, installations and equipment and industrial products Structuring principles and reference designations Part 2: Classification of objects and codes for classes - CISPR 11 (mod) 2009 Industrial, scientific and medical equipment - EN 55011 Radio-frequency disturbance characteristics Limits and methods of measurement 2009 Use of conventional touch voltage limits Application guide BS EN 61439-1:2011 EN 61439-1:2011 -7Publication Year Title EN/HD Year CISPR 22 - Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement EN 55022 - ISO 178 2001 Plastics - Determination of flexural properties EN ISO 178 ISO 179 Series Plastics - Determination of Charpy impact properties EN ISO 179 Series ISO 2409 2007 Paints and varnishes - Cross-cut test EN ISO 2409 2007 ISO 4628-3 2003 EN ISO 4628-3 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance Part 3: Assessment of degree of rusting 2003 ISO 4892-2 2006 Plastics - Methods of exposure to laboratory light sources Part 2: Xenon-arc lamps EN ISO 4892-2 2006 2003 BS EN 61439-1:2011 EN 61439-1:2011 -8- Annex ZZ (informative) Coverage of Essential Requirements of EC Directive 2004/108/EC This European Standard has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association and within its scope the standard covers all relevant essential requirements as given in Article of Annex I of the EC Directive 2004/108/EC This Part of the EN 61439 series alone does not give presumption of conformity with the essential requirements of the EMC Directive without another relevant part of the series (e.g EN 61439-2 for power switchgear and controlgear assemblies) These product parts call up the applicable EMC requirements of EN 61439-1 for assemblies within their specific scope WARNING: Other requirements and other EC Directives may be applicable to the products falling within the scope of this standard BS EN 61439-1:2011 61439-1 © IEC:2011 – 128 – Annex N (normative) Operating current and power loss of bare copper bars The following tables provide values for conductor operating currents and power losses under ideal conditions within an ASSEMBLY (see 10.10.2.2.3, 10.10.4.2.1 and 10.10.4.3.1) This annex does not apply to conductors verified by test The calculation methods used to establish these values are given to enable values to be calculated for other conditions Table N.1 – Operating current and power loss of bare copper bars with rectangular cross-section, run horizontally and arranged with their largest face vertical, frequency 50 Hz to 60 Hz (ambient temperature inside the ASSEMBLY: 55 °C, temperature of the conductor 70 °C) Height x thickness of bars Crosssectional area of bar One bar per phase Operating Power-losses current per phase conductor P v k3 mm 23,5 1,00 15 × 29,5 15 × 44,5 20 × Two bars per phase (spacing = thickness of bars) k3 Operating current Power-losses per phase conductor Pv W/m 6,4 A 70 W/m 4,5 1,01 A 118 1,00 83 5,0 1,01 138 7,0 1,01 105 5,4 1,02 183 8,3 39,5 1,01 105 6,1 1,01 172 8,1 20 × 59,5 1,01 133 6,4 1,02 226 9,4 20 × 99,1 1,02 178 7,0 1,04 325 11,9 mm × mm 12 × 20 × 10 199 1,03 278 8,5 1,07 536 16,6 25 × 124 1,02 213 8,0 1,05 381 13,2 30 × 149 1,03 246 9,0 1,06 437 14,5 30 × 10 299 1,05 372 10,4 1,11 689 18,9 40 × 199 1,03 313 10,9 1,07 543 17,0 40 × 10 399 1,07 465 12,4 1,15 839 21,7 50 × 249 1,04 379 12,9 1,09 646 19,6 50 × 10 499 1,08 554 14,2 1,18 982 24,4 60 × 299 1,05 447 15,0 1,10 748 22,0 60 × 10 599 1,10 640 16,1 1,21 1118 27,1 80 × 399 1,07 575 19,0 1,13 943 27,0 80 × 10 799 1,13 806 19,7 1,27 1372 32,0 499 1,10 702 23,3 1,17 1125 31,8 999 1,17 969 23,5 1,33 1612 37,1 1200 1,21 1131 27,6 1,41 1859 43,5 100 × 100 × 10 120 × 10 Pv = where Pv is the power loss per metre; I is the operating current; k3 is the current displacement factor; I × k3 × [1+ α × (Tc − 20 °C)] κ×A BS EN 61439-1:2011 61439-1 © IEC:2011 – 129 – m κ is the conductivity of copper, κ = 56 A is the cross-sectional area of bar; α is the temperature coefficient of resistance, α = 0,004 K –1 ; Tc is the temperature of the conductor Ω × mm ; The operating currents may be converted for other ambient air temperatures inside the ASSEMBLY and/or for a conductor temperature of 90 °C by multiplying the values of Table N.1 by the corresponding factor k from Table N.2 Then the power losses shall be calculated using the formula given above accordingly Table N.2 – Factor k for different temperatures of the air inside the ASSEMBLY and/or for the conductors Air temperature inside the enclosure around the conductors °C Factor k4 Conductor temperature of 70 °C Conductor temperature of 90 °C 20 2,08 2,49 25 1,94 2,37 30 1,82 2,26 35 1,69 2,14 40 1,54 2,03 45 1,35 1,91 50 1,18 1,77 55 1,00 1,62 60 0,77 1,48 It shall be considered that, dependent upon the design of the ASSEMBLY , quite different ambient and conductor temperatures can occur, especially with higher operating currents Verification of the actual temperature rise under these conditions shall be determined by test The power losses may then be calculated by the same method as used for this Table N.2 NOTE At higher currents additional eddy current losses may be significant which are not included in the values of Table N.1 – 130 – BS EN 61439-1:2011 61439-1 © IEC:2011 Annex O (informative) Guidance on temperature rise verification O.1 General All ASSEMBLIES generate heat in service Assuming the heat dissipation capability of the ASSEMBLY for local areas within the ASSEMBLY and for the ASSEMBLY as a whole, when operating on full load, exceeds the total heat produced then thermal equilibrium will be established; temperature will stabilize at a temperature rise above the ambient temperature surrounding the ASSEMBLY The purpose of temperature rise verification is to ensure temperatures stabilize at a value that will not result in: a) significant deterioration or ageing of the ASSEMBLY , or b) excessive heat being transferred to external conductors, such that the service capability of the external conductors and any equipment to which they are connected, may be impaired, or, c) people, operators or animals in the vicinity of an ASSEMBLY being burnt in normal operating circumstances O.2 Temperature-rise limits It is the manufacture’s responsibility to select the appropriate method for temperature rise verification (See Figure O.1) All the temperature rise limits given in the standard assume that the ASSEMBLY will be located in an environment where the daily average and peak ambient temperatures not exceed 35 ºC and 40 ºC, respectively The standard also assumes that all outgoing circuits within an ASSEMBLY will not be loaded to their rated current at the same time This recognition of the practical situation is defined by a ‘rated diversity factor’ Subject to the loading of the incoming circuit not exceeding its rated current, diversity is the proportion of the individual rated currents that any combination of outgoing circuits can carry continuously and simultaneously, without the ASSEMBLY overheating Diversity factor (assumed loading) is usually defined for the ASSEMBLY as a whole, but a manufacturer may choose to specify it for groups of circuits, for example the circuits in a section Temperature rise verification confirms two criteria, as follows: a) that each type of circuit is capable of carrying its rated current when it is incorporated in the ASSEMBLY This takes into account the way in which the circuit is connected and enclosed within the ASSEMBLY , but excludes any heating affects that may result from adjacent circuits carrying current b) the ASSEMBLY as a whole will not overheat when the incoming circuit is loaded to its rated current and, subject to the maximum current of the incoming circuit, any combination of outgoing circuits can be simultaneously and continuously loaded to their rated current multiplied by the rated diversity factor for the ASSEMBLY Temperature rise limits within the ASSEMBLY are the manufacturers’ responsibility, they are essentially determined on the basis of operating temperature not exceeding the long term capability of the materials used within the ASSEMBLY At interfaces between the ASSEMBLY and BS EN 61439-1:2011 61439-1 © IEC:2011 – 131 – the ‘wider world’, for example, cable terminals and operating handles, the standard defines temperature rise limits (see Table 6) Within boundaries defined in the standard, temperature rise verification can be undertaken by test, calculation or design rules It is permissible to use one or a combination of the verification methods set out in the standard to verify temperature rise performance of an ASSEMBLY This allows the manufacturer to choose the most appropriate method for the ASSEMBLY , or part of an ASSEMBLY , being considered, taking into consideration volumes, the construction, design flexibility, current rating and size of the ASSEMBLY In typical applications involving some adaptation of a standard design it is highly likely more than one method will be used to cover various elements of the ASSEMBLY design O.3 O.3.1 Test General In order to avoid unnecessary testing the standard provides guidance on selecting groups of comparable functional units It then details how to select the critical variant from the group for test Design rules are then applied to assign ratings to other circuits that are ‘thermally similar’ to the critical variant tested Three options for verification by test are offered in this standard O.3.2 Method a) – Verification of the complete ASSEMBLY (10.10.2.3.5) If several or all circuits of an ASSEMBLY are loaded simultaneously then the same circuit is only able to carry its rated current multiplied with the rated diversity factor (see 5.4), due to the thermal influence of the other circuits Thus to verify the rated currents of all circuits a separate test for each type of circuit is necessary To verify the rated diversity factor one additional test with simultaneous load on all circuits has to be done (see methods b) and c)) To avoid the large number of tests that may be necessary 10.10.2.3.5 describes a verification method where only one test is made with simultaneous load on all circuits Because with only one test the rated currents and the rated diversity factor of the circuits cannot be verified separately, it is assumed that the diversity factor is one In this case the load currents are equal to the rated currents This is a quick and conservative approach to achieving a result for a particular arrangement of ASSEMBLY It proves the rating of the outgoing circuits and the ASSEMBLY in the same test The incoming circuit and busbars are loaded to their rated current and as many outgoing circuits in a group as are necessary to distribute the incoming current, are loaded to their individual rated currents when installed in the ASSEMBLY For most installations this is an unrealistic situation since outgoing circuits are not normally loaded to unity diversity If the group of functional units tested does not include one of each of the different types of outgoing circuit incorporated in the ASSEMBLY , then further tests are carried out considering different groups of outgoing circuits until one of each type has been tested Testing in this manner requires the minimum number of temperature rise tests, but the test arrangement is more onerous than necessary and the result is not applicable to a range of ASSEMBLIES O.3.3 Method b) – Verification considering individual functional units separately and the complete ASSEMBLY (10.10.2.3.6) With this arrangement of testing each critical variant of outgoing circuit is tested separately to confirm its rated current and then the ASSEMBLY as whole is tested with the incoming circuit loaded to its rated current and groups of outgoing circuits, as necessary to distribute the – 132 – BS EN 61439-1:2011 61439-1 © IEC:2011 incoming current, loaded to their rated current multiplied by the diversity factor The group tested should include one outgoing circuit of each critical variant to be incorporated in the ASSEMBLY Where this is not practical, further groups are tested until all critical variants of outgoing circuit have been considered This test regime takes into account the diversity in the loading of outgoing circuits that is applicable in the majority of applications However, as in method a) above, the result is only applicable to a specific arrangement of ASSEMBLY tested O.3.4 Method c) – Verification considering individual functional units and the main and distribution busbars separately as well as the complete ASSEMBLY (10.10.2.3.7) This test method enables modular systems to be temperature rise verified without the need to test every conceivable combination of circuits Temperature rise tests are carried out separately to prove the rating of: a) functional units, b) main busbars, c) distribution busbars, d) complete ASSEMBLY To verify the performance of the ASSEMBLY as a whole, these tests are then complimented by a test on a representative ASSEMBLY in which the incoming circuit is loaded to its rated current and the outgoing circuits are loaded to their rated current multiplied by the diversity factor Whilst this approach requires more testing than methods a) and b) it has the advantage that the modular system rather than a specific arrangement of ASSEMBLY is verified O.4 O.4.1 Calculation General Two methods of verifying temperature rise performance by calculation are included within the standard O.4.2 Single compartment assembly with a rated current not exceeding 630 A A very simple method of temperature rise verification that requires confirmation that the total power loss of the components and conductors within the ASSEMBLY not exceed the known power dissipation capability of the enclosure The scope of this approach is very limited and in order that there are no difficulties with hot spots, all components must be de-rated to 80 % of their free air current rating O.4.3 assembly with rated currents not exceeding 600 A Temperature rise verification is by calculation in accordance with IEC 60890 with additional margins The scope of this approach is limited to 600 A, components are de-rated to 80 % of their free air rating or less and any horizontal partitions must have, as a minimum, a 50 % open area O.5 Design rules The standard allows, in clearly defined circumstances, for the derivation of ratings from similar variants that have been verified by test For example, if the current rating of a double lamination busbar has been established by test, it is acceptable to assign a rating equal to BS EN 61439-1:2011 61439-1 © IEC:2011 – 133 – 50 % of the tested arrangement to a busbar comprising a single lamination with the same width and thickness as the tested laminations, when all other considerations are the same In addition, the rating of all circuits within a group of comparable functional units (all devices must be of the same frame size and belong to the same series) can be derived from a single temperature rise test on the critical variant within the group An example of this may be to test a nominal 250 A outgoing circuit breaker and establish a rating for it in the ASSEMBLY Then, assuming the same frame size breaker is being considered and other specified conditions are met, verify by calculation the rating of a nominal 160 A circuit breaker within the same enclosure Lastly, in respect of temperature rise, there are very strict design rules that permit the substitution of a device with a similar device from another series or even another make, without retesting In this case, in addition to the physical arrangement being essentially the same, the power loss and terminal temperature rise of the substitute device, when it is tested in accordance with its own product standard, must not be higher than those of the original device NOTE When considering device substitution all other performance criteria, in particular that dealing with short circuit capability, should be considered and satisfied, in accordance with the standard, before an A SSEMBLY is deemed to be verified Method c) verification of f.u and busbars separately and the complete ASSEMBLY; 10.10.2.3.7 Modular Is the ASSY of a singular or modular design Y N ASSY Does the have separate fu’s ? N Is a single test to be carried out ? Verification by derivation10.10.3 Y Y Method b) verification of f.u separately and the complete ASSEMBLY: 10.10.2.3.6 Method a) verification of the complete ASSEMBLY: 10.10.2.3.5 Select verification method f.u = functional unit = compartment comp Verification by calculation according to 10.10.4.3 Verification by calculation according to 10.10.4.2 = ASSEMBLY Y Y A SSY Key N Is the ASSY a multiple comp up to 600 A N Is the ASSY a single comp up to 630 A Verification based on calculation Figure O.1 – Temperature rise verification methods Method a) verification of the complete ASSEMBLY: 10.10.2.3.5 Singular (particular arrangement) Selection of the representative arrangement: 10.10.2.2 N Is the design covered by an existing design Verification based on test/derivation Verification of temperature rise 10.10 IEC 1860/11 – 134 – BS EN 61439-1:2011 61439-1 © IEC:201 BS EN 61439-1:2011 61439-1 © IEC:2011 – 135 – Annex P (normative) Verification of the short-circuit withstand strength of busbar structures by comparison with a tested reference design by calculation P.1 General This annex describes a method for assessing the short-circuit withstand strength of busbar structures of an ASSEMBLY by a comparison of the ASSEMBLY to be assessed with an ASSEMBLY already verified by test (see 10.11.5) P.2 Terms and definitions For the purposes of this annex, the following terms and definitions apply P.2.1 tested busbar structure TS structure whose arrangement and equipment are documented by drawings, parts lists and descriptions in the test certificate (Figure P.1) Side view I1 I2 2 I3 4 b I3 b IEC 1861/11 Key a, b, I busbar support busbar connection equipment connection distances Figure P.1 – Tested busbar structure (TS) BS EN 61439-1:2011 61439-1 © IEC:2011 – 136 – P.2.2 non tested busbar structure NTS structure which requires verification of short-circuit withstand strength (Figure P.2) Side view I > I1 I2 2 I5 I3 4 b I3 b IEC 1862/11 Key a, b, I busbar support busbar connection equipment connection distances Figure P.2 – Non tested busbar structure (NTS) BS EN 61439-1:2011 61439-1 © IEC:2011 P.3 – 137 – Method of verification The short-circuit withstand strength of a derived structure, i.e an NTS, is verified from a tested structure (TS) by applying calculations according to IEC 60865-1 to both structures The short-circuit withstand strength of the NTS is considered verified if the calculations show that the NTS does not have to withstand higher mechanical and thermal stresses than the tested structure P.4 P.4.1 Conditions for application General Changes of parameters, such as busbar clearances, busbar material, busbar cross-section and busbar configuration shown to be necessary by the calculation in conformity with IEC 60865-1 are permissible only in so far as the following conditions are adhered to P.4.2 Peak short-circuit current The short-circuit current may be changed only to lower values P.4.3 Thermal short-circuit strength The thermal short-circuit strength of an NTS shall be verified by calculations according to IEC 60865-1 The calculated temperature rise of the NTS shall not be higher than that of the TS P.4.4 Busbar supports Changes of material or shape of supports taken from an ASSEMBLY verified by test are not permitted However, other supports may be used but they shall have been previously tested for the required mechanical strength P.4.5 Busbar connections, equipment connections The type of busbar and equipment connections shall have been previously verified by test P.4.6 Angular busbar configurations IEC 60865-1 is applicable only to straight busbar configurations Angular busbar configurations may be considered as a series of straight configurations when supports are provided at the corners (see Figure P.3) – 138 – BS EN 61439-1:2011 61439-1 © IEC:2011 d1 d2 IEC 1863/11 Key busbar support equipment connection d support distance Figure P.3 – Angular busbar configuration with supports at the corners P.4.7 Calculations with special regard to conductor oscillation For calculations in conformity with IEC 60865-1 on the tested structure (TS), the following values of the factors V σ , V σs and V F shall be used: V σ = V σs = V F = 1,0 where Vσ is the ratio between dynamic and static main conductor stress; V σs is the ratio between dynamic and static sub-conductor stress; VF is the ratio between dynamic and static force on support For the NTS, V σ = V σs = 1,0 and V F is found from calculations in accordance with IEC 60865-1, but V F < 1,0 is to be replaced by V F = 1,0 BS EN 61439-1:2011 61439-1 © IEC:2011 – 139 – Bibliography IEC 60038, IEC standard voltages IEC 60050-151:2001, International Electrotechnical Vocabulary – Part 151: Electrical and magnetic devices IEC 60050-195:1998, International Electrotechnical Vocabulary – Part 195: Earthing and protection against electric shock IEC 60050-441:1984, International Electrotechnical Vocabulary – Chapter 441: Switchgear, controlgear and fuses IEC 60050-471:2007, International Electrotechnical Vocabulary – Part 471: Insulators IEC 60050-601:1985, International Electrotechnical Vocabulary – Chapter 601: Generation, transmission and distribution of electricity – General IEC 60050-604:1987, International Electrotechnical Vocabulary – Chapter 604: Generation, transmission and distribution of electricity – Operation IEC 60050-826:2004, installations International Electrotechnical Vocabulary – Part 826: Electrical IEC 60079 (all parts), Explosive atmospheres IEC 60092-302:1997, Electrical installations in ships – Part 302: Low-voltage switchgear and controlgear assemblies IEC 60112:2003, Method for the determination of the proof and the comparative tracking indices of solid insulating materials IEC 60204 (all parts), Safety of machinery – Electrical equipment of machines IEC 60204-1, Safety of machinery – Electrical equipment of machines – Part 1: General requirements IEC 60227-4:1992, Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 4: Sheathed cables for fixed wiring IEC 60228:2004, Conductors of insulated cables IEC 60417-SN:2011, Graphical symbols for use on equipment IEC 60502-1:2004, Power cables with extruded insulation and their accessories for rated voltages from kV (U m = 1,2 kV) up to 30 kV (U m = 36 kV) – Part 1: Cables for rated voltages of kV (U m = 1,2 kV) and kV (U m = 3,6 kV) IEC 60947 (all parts), Low-voltage switchgear and controlgear IEC 61000-3-2:2005, Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for harmonic current emissions (equipment input current ≤ 16 A per phase) – 140 – BS EN 61439-1:2011 61439-1 © IEC:2011 IEC 61000-3-3, Electromagnetic compatibility (EMC) – Part 3-3: Limits – Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current ≤16 A per phase and not subject to conditional connection IEC 61000-3-5, Electromagnetic compatibility (EMC) – Part 3-5: Limits – Limitation of voltage fluctuations and flicker in low-voltage power supply systems for equipment with rated current greater than 75 A IEC 61000-3-11, Electromagnetic compatibility (EMC) – Part 3-11: Limits – Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems – Equipment with rated current ≤ 75 A and subjet to conditional connection IEC 61000-3-12, Electromagnetic compatibility (EMC) – Part 3-12: Limits – Limits for harmonic currents produced by equipment connected to public low-voltage systems with input current > 16 A and ≤ 75 A per phase IEC 61000-6-1, Electromagnetic compatibility (EMC) – Part 6-1: Generic standards – Immunity for residential, commercial and light-industrial environments IEC 61000-6-2, Electromagnetic compatibility (EMC) – Part 6-2: Generic standards – Immunity for industrial environments IEC 61000-6-3, Electromagnetic compatibility (EMC) – Part 6-3: Generic standards – Emission standard for residential, commercial and light-industrial environments IEC 61082 (all parts), Preparation of documents used in electrotechnology IEC/TR 61117:1992, A method for assessing the short-circuit withstand strength of partially type-tested assemblies (PTTA) IEC 61140:2001, Protection against electric shock – Common aspects for installation and equipment IEC 61241(all parts), Electrical apparatus for use in the presence of combustible dust IEC/TR 61912-1:2007, Low-voltage switchgear and controlgear – Overcurrent protective devices – Part 1: Application of short-circuit ratings IEC/TR 61912-2:2009, Low-voltage switchgear and controlgear – Over-current protective devices – Part 2: Selectivity under over-current conditions DIN 43671:1975, Copper busbars; 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